1. Technical Field
The present invention relates to lane departure warning and avoidance systems, adapted for use with a vehicle, and more particularly, to a selectable lane departure warning and avoidance system configured to detect a spatial relationship between the vehicle and the boundaries of a lane, and to incorporate operator or vehicular input in the warning decision making algorithm.
2. Background Art
Lane departure warning and avoidance (LDW) systems have been developed to aid the orderly navigation of thoroughfares by vehicle operators. More particularly, these traffic safety systems assist operators (i.e. drivers) in maintaining proper lane alignment by alerting the operator to a possible unintentional lane departure. Unlike scarifications and other measures commonly found on thoroughfare shoulders that alert the operator only after he or she has traversed the lane-marking, LDW systems provide timely warnings prior to lane departure. Further, LDW systems offer effective warning alerts for vehicles in central lanes, and adjacent on-coming traffic, whereas shoulder methods are ineffective.
These LDW systems typically utilize at least one radar/lidar, DGPS/INS and digital map, or camera/video processing sensor to detect the lane markings that delineate a lane boundary. The detected lane-marking range is typically used to determine the lateral position of the vehicle in the lane (i.e., vehicle in-lane position), and a parameter time-to-lane-cross (TTLC) is calculated based on the in-lane position and the motion of the vehicle. If the TTLC is smaller than a predefined threshold, a warning is typically issued. Other lateral support systems, such as lane keeping (LK) systems, have similarly been developed.
These LDW systems, however, typically present one-size-fits-all solutions, and do not accommodate the variation in driving styles of different drivers. For example, while negotiating a curve, an operator may elect to perform a “sporty driving maneuver” by intentionally encroaching upon the radially inner lane-marking, and reducing the curvature of his or her projected path, so as to maximize the potential of vehicle lateral acceleration, and tolerate a larger lateral deviation. Under these circumstances, a fixed threshold may trigger a nuisance alarm, as the operator approaches the lane-marking and continues to hug the curve. Needlesstosay, this results in inconvenience and/or distraction to the operator.
Thus, there is a need in the art for a lane departure warning system that is modifiable based on operator driving preference, and more preferably, self-adjusting based on vehicular input.